"It is outrageous that we have to ask for this. The Labour Party pays mere lip service to International Women's Day. ... Young women are deterred from coming because there is no provision for their babies. Those who do are not even allowed to bring their toddlers into the gallery."In 1975 she introduced the Balance of Sexes Bill with the objective to require men and women on public bodies in equal numbers. She had identified 4500 jobs appointed by Ministers, and 174 public bodies that were almost entirely male. In her speech to introduce the second reading of the Bill, she commended changes that had been made to the nominations process for the 'central list' from which candidates for government bodies could be selected, although she doubted that it was sufficiently broad to encourage applications from all areas of society. The Bill did not become law.
In 1976, Colquhoun was among nine Labour MPs advocating in a letter to The Times an "alternative policy" on Northern Ireland, including the removal of British troops from the country. She drew a negative response from members of her constituency party, in an area with a significant non-white population, for appearing to defend Enoch Powell in January 1977.
"I am rapidly concluding that Mr Powell, whom I had always believed to be a racialist before I went into the House of Commons, is not one".
She thought that sometimes it was wrong for members of her party to stop listening to what he was saying, and that the "real bogeymen are in the Labour Party" who do not improve the conditions for people in the multi-racial inner-cities. In February 1977, she expressed regret for her comments to her constituency party, withdrew any suggestion she supported Powell's opinions, and affirmed her support for a multi-racial society.
In 1979, she introduced the Protection of Prostitutes Bill into the House of Commons, turning up with 50 prostitutes in order to campaign for the decriminalisation of prostitution.
Colquhoun was deselected due to her sexuality and her feminist views; in late September 1977, members of her constituency party's General Management Committee voted by 23 votes to 18, with one abstention, to deselect her, citing her "obsession with trivialities such as women's rights". The local party chairman Norman Ashby said at the time:
"She was elected as a working wife and mother ... this business has blackened her image irredeemably".
"My sexuality has nothing whatever to do with my ability to do my job as an MP", Colquhoun insisted in an article for Gay News in October 1977.The vote by her constituency party was overruled in January 1978, as supporters of Colquhoun appealed to the National Executive Committee, who agreed that Colquhoun had been unfairly dismissed owing to her sexual orientation. Colquhoun wanted to put the past behind her and work with her local party, but the Vice-Chair of the General Management Committee said he thought that was impossible as many members were unwilling to work for Colquhorn's re-election, the prospects for which he thought were not promising. At the 1979 general election, she lost her seat to the Conservative Antony Marlow on an 8% swing.
She divorced her husband in 1980. Babs Todd was still her partner at Todd's death on 13 February 2020. Colquhoun died on 2 February 2021 at the age of 92.